Such a power chain saw handle as that with which the invention is concerned is used primarily for supporting and manipulating the angle of the saw during operation. There is, in addition, another handle usually found on power chain saws, for holding with the other hand to assist in guiding the manipulation of the chain saw, and it is located at the rear of the saw housing. This second type of handle usually has a trigger for controlling motor speed, and since the second handle is smaller without the stress that is developed in the first-described support handle, it has not experienced the problems that have plagued the support handle, particularly during operation.
Because of the severity of the manipulations that motor-driven chain saws, of the type with which the invention is concerned, are subjected, they customarily have two handles; one located at the center of gravity of the saw so that the saw can be supported and manipulated easily by the operator and a second handle, located at the rear of the saw housing, with an adjustable position switch for controlling motor speed. This second handle, although smaller than the first, is used also for a certain amount of guiding of the saw.
With these two handles, such motor-driven chain saws of the prior art can be supported and guided securely by the operator with both hands during operation. One such motor-driven chain saw is identified as Type 034 and is manufactured by Andreas Stihl. In this chain saw, the supporting and manipulating handle is attached to the saw housing on the underside thereof and extends completely around the saw housing in a spaced apart manner in a plane that includes or is in the region of the center of gravity of the saw.
The guiding handle, located at the rear of the saw housing, can be grasped by either the right or left hand of an operator. The supporting and manipulating handle, located forward of the guiding handle, therefore, must be constructed to permit grasping by the other hand of the operator, that is, from a position to the right or left of the saw housing, as well as from the top.
Several attempts have been made in the past to strengthen and to reinforce the supporting and manipulating handle. For example, one arrangement that has provided a measure of stability is a strut that is attached to the handle at its top, to one side of center, however, so that it extends downwardly and rearwardly and is attached to the saw housing. A reason for attaching the strut to one side of center is that it leaves the center free for grasping by the operator, which is where it is grasped from either side to support the saw from the top. This strut supported handle is described in U.S. Pat. No. 4,693,106.
Operators of chain saws have been known to cut the bail-type handle in half and then slip a piece of pipe over the handle. However, such field solutions often provide a loose fit and provide no support where the above-mentioned strut is attached to the handle.
The handle that is termed above as a supporting and manipulating handle is known also as a bail-type handle because it extends around the entire saw housing. This handle often is damaged or destroyed during use when it breaks loose from the saw housing at one of its points of attachment. Usually, the operator does not notice that this has occurred and continues use until damage is severe.